The present invention relates to methods and apparatus for distributing power to consumer devices, and more particularly to methods and apparatus for distributing power to consumer devices used by passengers on a mobile platform.
An increasing number of travelers today are using portable computer devices and other electronic items. Thus, requests by travelers for power ports or sockets at airline seats are becoming more common. In response to these requests, many airlines have seat power ports that are equipped to power everything from laptop computers to handheld video and DVD players. Power at 15 VDC is provided at airline seat power ports by passenger amenity power distribution systems that are designed for an expected maximum power consumption of 50 to 100 watts per seat (as determined by the airline company), plus an extra margin of about 20%. Because of available margins, the nominal power consumption of most carry-on consumer electrical apparatus, and the incorporation of overcurrent protection circuits elsewhere in the distribution system, individual seat power ports have not been provided with individual overcurrent protection circuits.
As new electrical devices and passenger amenities are becoming available, some passengers now want to use more than one electrical device at the same time. Thus, some passengers are carrying and using power strips or adapters that allow connection of multiple electrical devices to a single seat power port. As a result, the expected maximum power consumption at that seat power port may be exceeded. Some excess consumption by one or a few passengers is not troublesome because the margins designed into the distribution system allows a few extra devices per plane to go unnoticed. However, if a sufficient number of passengers draw excess current from their seat power ports, a portion of the amenity power distribution system may be shut down even though a branch circuit breaker may not have tripped. Such a shutdown may inconvenience not only the passengers drawing excess current, but other passengers as well. In addition, certain revenue-generating passenger communication systems powered by amenity power distribution systems on some airlines (for example, mobile Internet access systems) may also be disrupted.
There is therefore provided, as one aspect of the present invention, a power splitter device having a power input port, at least three power output ports that each have a separate, resettable overcurrent protection circuit with a maximum current rating; and a port switch configured to provide power from the input port to selectable combinations of one or more of the output ports. The combinations of one or more of the output ports include at least one combination of at least two of the output ports. In addition, the port switch is configured to prevent power from being applied to all of the output ports simultaneously.
In another aspect of the present invention, a power distribution system is provided. The power distribution system has a power source configured to provide power to a plurality of seat connectors, a branch level overprotection circuit having a maximum current rating and providing overcurrent protection for current drawn in a branch of the system that has a plurality of seat connectors; and a power splitter device. The power splitter device has a power input port configured to receive power from one of the seat connectors, at least three power output ports and a port switch. The three power ports each have a separate, resettable port level overcurrent protection circuit having its own maximum current rating. The port switch is configured to provide power from the input port to selectable combinations of one or more of the output ports and is also configured to prevent power from being applied to all of the output ports simultaneously. The selectable combinations of one or more output ports that can be powered include at least one combination of two or more ports.
In yet another aspect of the present invention, a method for supplying power to a plurality of passenger devices at a passenger seat of a mobile platform is provided. The method includes selecting a combination of one or more output ports to be powered by the seat connector utilizing a port switch, wherein each output port has a separate overcurrent protection circuit having its own maximum current rating, and restricting the port switch from selecting combinations of output ports having overcurrent protection circuits with maximum ratings having a total greater than a preselected maximum current. Combinations selectable by the port switch include at least one combination of two or more output ports out of at least three output ports.
Configurations of the present invention advantageously allow power to be provided to more than one power output ports, thereby allowing more than one consumer electronic device to be utilized at the same time even though each electronic device requires a separate power output port. Some configurations of the present invention also limit a total amount of current that can be drawn by a passenger on a mobile platform and protect tripping of branches of power systems resulting from passenger overloads.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.